1. Field of the Invention
The present invention relates generally to a composite molded product, a production process and an apparatus therefor. More specifically, the invention relates to a composite molded article to be used as interior parts of a vehicle or so forth, exterior parts of an acoustic instrument or so forth, in which a skin material and a base member are integrally molded, a production process thereof, and an apparatus therefor.
2. Description of the Related Art
Conventionally, as interior parts of a vehicle or so forth, such as a lining of a vehicular door, a rear parcel shelf and so forth, a composite molded products, in which skin materials and base members are molded integrally, have been widely used.
On the other hand, in the recent years, for the purpose of enhancement of acoustic effect in a vehicular cabin or so forth, speakers are arranged in various positions in the vehicular cabin. In such a case, it is typical to preliminarily form an opening in the lining or so forth at a corresponding position to a speaker position and to fit a separately formed speaker cover or a speaker grill within the opening in order to affect for acoustic effect.
One example of a conventional rear parcel shelf is illustrated in FIGS. 10A and 10B. In FIG. 10A, a rear parcel shelf main body 100 is prepared as an intermediate product by bonding a skin material after molding a base body of a resin with openings 102 for acoustic speaker and an opening 104 for ventilation, or, in the alternative, by forming the openings 102 and 104 for the acoustic speaker and ventilation after molding the base body resin and the skin material simultaneously as a composite molded product. On the other hand, two speaker grills 106 and four ventilation grills (hereinafter referred to as xe2x80x9cdrafter grillxe2x80x9d) 108 are prepared separately and fixed in the openings 102 and 104 of the main body 100 by means of resin clips or so forth after engaging and positioning therein, for obtaining a finished product shown in FIG. 10B.
However, the method, in which the speaker grills and the drafter grills are formed separately from the rear parcel shelf main body, has no problem in the acoustic effect, but encounters a problem in complicatedness in color matching or so forth and in cost for requiring separate molding dies and so forth.
As a solution for the problems set forth above, there have been proposed technologies to perform formation of openings in the base member and integrally forming of the base member and the skin material, simultaneously, as disclosed in Japanese Patent Application Laid-Open Nos. Heisei 6-15671, Heisei 6-15672 and Heisei 6-15673.
Namely, the disclosed in the foregoing publications are directed to the molded product in which a base member formed with a through opening for passing a sound and a surface material are integrally molded in the form of including the through opening, or in the form of excluding the through opening, simultaneously.
However, in such a conventional skin material integrated composite molded product, when it is applied for a rear parcel shelf, the skin material is exposed over the entire surface of the base member. In this case, in order to assure sufficient strength required in view of durability for avoiding rupture and so forth by contacting with passengers, a diameter of the opening to be formed may be limited. On the other hand, for better propagation of acoustic vibration, it is preferred to have a greater opening ratio. In order to compromise these requirement, it becomes necessary to form a large number of small diameter openings.
For providing a large number of small diameter openings, it becomes inherent to provide forming pins and so forth in the number corresponding to number of openings to be formed. This makes forming dies complicated and results in high cost. Also, mold releasing characteristics is degraded to restrict material of the base member, board thickness and so forth.
Moreover, in the external appearance, at a portion corresponding to the speaker grill, only a flat skin material is present. As a result, there is no room for designing for obtaining a superior external appearance.
In view of the problems in the prior art as set forth above, it is an object of the present invention to provide a composite molded product which can assure sufficient strength of a skin material irrespective of a diameter of an opening, and permit optimal setting of an external appearance depending upon a portion to be applied.
Another object of the present invention is to provide a production process which can produce the above-mentioned composite molded product at low cost.
A further object of the present invention is to provide a production apparatus which can produce the above-mentioned composite molded product at low cost.
In a first aspect of the present invention, there is provided a composite molded product comprising:
a main body formed of a base material of a thermoplastic resin and defining at least one through opening;
a porous skin material integrally molded with the main body by thermal fusing; and
at least one rib molded on a surface of the skin material at a position corresponding to the position of the at least one through opening, the rib being integrated with the main body through porous structure of the skin material.
Here, the main body may have at least one bridging member defining a plurality of through openings underlying the skin material, and the rib is arranged perpendicularly to the bridging member.
The at least one rib may be a plurality of parallel ribs.
The at least one rib may be a plurality of concentric ribs.
The at least one rib may be a mesh-shaped configuration, and the at least one bridging member is a honeycomb-shaped configuration.
The composite molded product may be used as an interior part of a vehicle.
The composite molded product may be used as an exterior part of an acoustic instrument.
In a second aspect of the present invention, there is provided a production process of a composite molded product comprising the steps of:
providing a first molding die having at least one opening forming member projecting from a first forming surface and having a predetermined dimension in lengthwise direction;
providing a second molding die having at least one rib forming groove on a second forming surface at a position corresponding to a position of the at least one opening forming member;
arranging a porous skin material between the first and second forming dies;
supplying a base material of a thermoplastic resin at least before curing, into a cavity defined between the first and second molding dies at the first forming die side of the skin material; and
clamping the first and second molding dies and applying a pressure for performing pressure molding.
The rib forming groove may be a length longer than the predetermined dimension in the length wise direction.
The opening forming member may be movable relative to the first molding die, and contacts with the second forming surface of the second molding die at initial stage of clamping step.
In a third aspect of the present invention, there is provided a producing apparatus for a composite molded product comprising:
a first molding die having at least one opening forming member projecting from a first forming surface and having a predetermined dimension in lengthwise direction;
a second molding die having at least one rib forming groove on a second forming surface at a position corresponding to a position of the at least one opening forming member;
supporting means provided in the second molding die for supporting a porous skin material; and
pressurizing means for clamping the first and second molding dies and applying a pressure for performing pressure molding for a thermoplastic resin at least before curing in a cavity defined between the first and second molding dies.
The rib forming groove may be longer than the predetermined dimension in lengthwise direction.
The opening forming member may be movable relative to the first molding die, and contacts with the second forming surface of the second molding die at the initial stage of clamping of the first and second molding dies.
The opening forming member may comprise a plurality of pins arranged in parallel relationship with a given gap, and the rib forming groove is longer than a total dimension of the plurality of pins in lengthwise direction.
The first molding die may have a separately formed guide portion slidably guiding the opening forming member, and the second molding die has a separately formed exchangeable portion defining the rib forming groove.
The rib forming groove may be formed in a direction perpendicular to a direction along which the given gap between the plurality of pins extends.
The opening forming member may be formed with a predetermined pattern on a top surface thereof.
The rib forming groove may be in mesh-shaped configuration, and the predetermined pattern is a honeycomb-shaped groove.
As set forth above, with the present invention, the composite molded product is constructed with the main body formed of a base material with at least one through opening, the skin material integrated with the main body by thermal fusing, and at least one rib at the position corresponding to the through opening, which rib is integral with the main body, extended through the skin material, and formed simultaneously with the main body, the skin material can be protected satisfactorily irrespective of the size of the through opening. Furthermore, with the construction set forth above, greater freedom is provided in designing the composite molded product so that optimum external appearance can be selected depending upon application thereof. Furthermore, the composite molded product according to the present invention can be produced at low cost.
Also, in the preferred construction, a plurality of through openings are defined by at least one bridging member, and the rib is arranged perpendicularly to the bridging member. With such construction, the composite molded material superior in strength can be obtained.
Here, since the shape of the rib can be selected in wide variations, such as parallel straight ribs, concentric ribs, honeycomb-shaped rib, mesh-shaped rib and so forth, the range of selection of the configuration of the rib can be significantly widened depending on types of usage.
In the production process of the composite molded product set forth above, according to the present invention, the product is produced by arranging the skin material between a first (lower) molding die with at least one opening forming member projecting from the forming surface and having a dimension corresponding to the desired dimension of the opening, and a second (upper) molding die defining at least one rib forming groove, supplying the molten or at least non cured thermoplastic resin in the cavity defined between the first and second molding dies at the first molding die side of the skin material, and applying a pressure by clamping to perform pressure molding. Therefore, the molten or non-cured resin can be supplied in a condition where the die is held open, and the metsuke amount (g/m2) of the skin material can be minimized. Thus, the composite molded product can be formed easily at low cost.
The producing apparatus of the composite molded product according to the present invention is constructed with the first molding die having at least one opening forming member projecting from the forming surface and having dimension corresponding the opening to be formed, the second molding die having at least one rib forming groove at the position corresponding to the position of the opening forming member, a supporting member provided in the second molding die and supporting the porous skin material and a pressurizing means for clamping the first and second molding dies to apply a pressure to the non-cured thermoplastic resin in the cavity. Thus, desired composite molded product can be formed easily at low cost.
Also, in the preferred construction, since the length of the rib forming groove is set to be longer than the dimension in the lengthwise direction of the pin array, a flow efficiency of the resin into the rib forming groove can be higher to improve quality of the product.
In the further preferred embodiment, since the opening forming member is provided for movement relative to the first molding die to contact with the forming surface of the second molding die at the initial stage of clamping process, it makes unnecessary to adjust the distance between the opening forming member in the first molding die and the forming surface of the second molding die to facilitate formation of the opening.
In the preferred construction, the first molding die has a separately formed and exchangeably provided guiding portion which slidably guides the opening forming member, and the second molding die is provided a separately formed portion defining the rib forming groove so that configuration of the grill can be varied without exchanging entire die.